the 350-point plunge comes just as the government says the economy is getting better. everything from housing to jobs, to consumer spending, all showing improvement. so, why would wall street run scared from such good news? experts say, it's all because fed chair ben bernanke, basically our country's banker in chief, now wants to take the training wheels off our economy. saying because things are looking up, it's time to dial back on trillions of dollars the fed's been pouring into the markets. >> we've had training wheels on for quite some time now. and now, we're getting word that they're going to have to come off slowly. and we have to see if we can ride this bike on our own. >> reporter: but riding without that help means the cost of borrowing money to do everything from buying a house to starting a business is going up. and that spooks the stock market. and staying on that training wheels theme, traders here on wall street aren't afraid we're going to crash into a wall when the wheels come off. what they're concerned about is things could get wobbly. that means un